Various medical procedures, particularly cardiology procedures, involve accessing a corporeal vessel or other lumen through a percutaneous insertion sheath. The insertion sheath necessarily requires the formation of a hole or opening in the vessel wall so that a medical procedure can be performed via the insertion sheath. After the particular medical procedure has been performed, the insertion sheath must eventually be removed from the vessel and the access hole in the vessel wall must be closed.
A number of prior vascular closure devices have been developed to close the vessel wall. Closing the vessel wall typically involves packing a resorbable sealing plug at the hole or sandwiching the hole between the sealing plug and an anchor. Examples of prior vascular closure devices are described in U.S. Pat. Nos. 6,179,863; 6,090,130; and 6,045,569 and related patents that are hereby incorporated by reference.
However, prior to a successful deployment of the sealing plug or another vascular tool, the insertion sheath must be properly located within the vessel or other lumen. Proper placement of the insertion sheath enables proper placement of the sealing plug or insertion of a vascular tool.
According to conventional techniques, proper placement of the insertion sheath is accomplished with the aid of a puncture locator. Typically a puncture locator and the insertion sheath are inserted through the hole in the vessel wall. The puncture locator provides a fluid communication path from a distal orifice (where the insertion sheath enters the vessel) to a proximal end, where blood flow can be observed by an operator. As the insertion sheath puncture locator assembly penetrates the vessel wall, blood flows through and out of the puncture locator. Blood exiting the puncture locator indicates that the insertion sheath has begun to penetrate the blood vessel. Blood will continue to flow through the puncture locator until the insertion sheath and/or the puncture locator are removed from the vessel.
While the puncture locator is usually helpful for properly positioning the insertion sheath, the use of the puncture locator is only a secondary indication of insertion sheath position. The blood flow through the puncture locator is an actual indication of the position of the puncture locator, and the relative positions of the puncture locator and the insertion sheath provide secondary indication of the location of the insertion sheath. The use of a separate puncture locator relies on the orientation of the puncture locator with respect to the insertion sheath. In addition, the use of the puncture locator adds an additional step to the process of positioning the insertion sheath. Moreover, once the puncture locator is removed from the insertion sheath, any movement of the insertion sheath out of position is not likely to be detected. It would be desirable to include one or more locating lumens in the insertion sheath. Providing locating lumens in the insertion sheath would provide direct indication of insertion sheath position, and facilitate detection of any subsequent mispositioning. However, it is not desirable to increase the outer diameter of current insertion sheaths beyond 6F and 8F sizes. A larger outer diameter requires a larger puncture, and a larger puncture is more difficult to close.
The present invention is directed to overcoming, or at least reducing the effects of, one or more of the problems outlined above.